I am of the understanding that if you go to Israel, you can't leave. And yet we see people doing this al the time – not only visitors to Israel, but people living there who take vacations in Europe or America, or go to visit relatives. Can you locate for me an authoritative responsa on this issue?
The Aish Rabbi Replies
The Talmud (Avodah Zara 13a) says that one may only leave Israel for one of two purposes: To get married and to learn Torah.
The reasons cited by the authorities are varied: Nachmanides (Numbers 33:53) explains the prohibition on account of the mitzvah to settle the land of Israel. Rashbam (Bava Batra 91b) explains that the prohibition exists because by leaving the land, one is actively removing oneself from the mitzvot that are uniquely dependent upon being present in Israel. The Lechem Mishnah (Melachim 5:12) explains that because Israel is holy, it is forbidden to leave it.
Besides that, there appear to be few exceptions. Most of the responsa we have do not distinguish between a visitor and resident. Perhaps before the advent of plane travel, when one went to Israel, he did not go just to visit.
May one leave Israel for business? Maimonides (Laws of Kings 5:9-12) writes that the only other acceptable reason to leave is in case of a famine, i.e. for the need to earn a livelihood. This is on condition that one returns to Israel as soon as business is done
Are there other exceptions?
• One may leave Israel in order to attend to his parents, under the mitzvah of honoring one's parents. (Tashbetz 3:288; Tzitz Eliezer 11:94 and 14:72)
• Certainly, one is permitted to leave Israel to seek medical care or for health reasons in general.
• It is permitted to travel to the gravesites of tzaddikim, in order to pray there. (Sha'arey Teshuvah 568:20)
• It is permitted to leave Israel to teach Torah to others. (Yechaveh Da'as 5:57)
• One may leave Israel to visit a good friend. (Mishnah Berurah 531:14)
But all of the above are conditional. One may leave but must return as soon as whatever he set out to do is taken care of. (see Yechaveh Daat 3:69, 5:57)
Is there a time limit? Maimonides lived in Israel, and then went to Egypt for the last few decades of his life. It would seem that Maimonides' mind-frame in Egypt was one of a temporary sojourner, with the intent to return to Israel as soon as the situation availed itself. Though we see that "temporarily" leaving Israel can last for many years.